


Once Again

by pupeez4eva



Category: Gravity Falls, Naruto
Genre: Alternate Universe - Canon Divergence, Crossover, Family, Gen, Humor, Mabel Pines is reborn as Sasuke, No Uchiha Massacre, Reincarnation
Language: English
Status: In-Progress
Published: 2019-01-01
Updated: 2019-04-11
Packaged: 2019-10-02 03:45:41
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 3
Words: 4,328
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/17256968
Author URL: https://archiveofourown.org/users/pupeez4eva/pseuds/pupeez4eva
Summary: If you asked anyone what they thought of Sasuke Uchiha, they'd say that he was cheerful, overly-hyper, and loved glitter and sweaters WAY too much.(Mabel Pines is reborn as Sasuke Uchiha. Unsurprisingly, this changes things a lot).





	1. Mabel

When Mabel Pines first woke up in this strange, new world, in a different body — a _baby's_ body and a _boy’s_ body — she was pretty confused. The realisation that she’d probably been reincarnated had come quickly, because it wasn’t exactly the strangest thing she’d ever come across. She would’ve been pretty proud of herself for figuring it out so soon if she hadn’t been too busy freaking out. 

 

She didn’t _want_ to be reincarnated! She just wanted to go wherever Dipper, and her parents and her Grunkles had gone after their deaths. Mabel had lived a long, fulfilled life, and she was ready to spend whatever came after death with the people she loved most.

 

She didn’t want to be a baby again, and definitely not one that didn’t have her twin brother by her side. 

 

She spends the first few days of her newborn life moping in her new mothers arms (and wow, was she pretty). Mabel was actually pretty jealous, because _hello —_ she was a _boy_ now, so there went any chance of her looking like _that._

 

Her new dad also visited quite a bit. She wasn’t sure what to think of him, other than that he seemed _way_ too formal, and kind of grumpy, which made her chest twinge because it reminded her of Grunkle Stan.

 

Eventually she decided that she’d just have to accept it for now. Maybe one day she’d bump into Dipper or her Grunkles around here. After all, if she’d ended up here, maybe it meant that they might as well? 

 

(She hoped so, because she _really, really_ missed them).

 

On the other hand, moping wasn’t going to do her any favours. It wasn’t even like she could hide in sweater town — a habit that hadn’t gone away even in her old age, much to Dipper’s amusement — because she was currently too young to even lift her head up by herself.

 

She decided to look on the bright side. She was a kid again, and being a kid was _fun,_ right? Way easier than being an adult, that was for sure. Being adult meant having a job, and paying bills and a mortgage. If she was a kid again — even if that wasn’t quite true, mentally at least — she’d be able to go on adventures again, and spend all her time knitting sweaters, and making new friends, and having impromptu dance sessions — all things she’d still done as an adult, but, well, doing it as a kid was quirky and charming right?

 

(In a few years, her new father would wholly disagree).

 

Also, it turned out she had a brother again. She had the fleeting sense that she was betraying Dipper by accepting this, but quickly overcame this. After all, you were allowed to have two brothers — Grunkles Stan and Ford had had each other, and then also had Grandpa Shermie. It wasn’t like she was replacing Dipper — she could never do that, and _never_ would — but being an only child just didn’t feel right, not when she’d spent her whole life with a brother by her side. She was kind of glad to have someone here too, even though she wasn’t quite sure what to think of him yet.

 

(Also, Itachi was kind of adorable, and had _very_ pretty hair. Mabel couldn't wait till she was old enough too actually gain control of her limbs, because she was _so_ playing hairdresser with him).

 

This was kind of like a new adventure, she told herself, as her new mum cooed over her, and her new brother watched her with wide eyes (he was _seriously_ adorable — oh god, Mabel just wanted to regain control of her motor movements so she could squish his cheeks). A whole new place to explore, and a whole bunch of potential friends.

 

She’d find some way to make this work.

 

…

 

Mabel spent four years in this new world, before she came to a series of revelations.

 

The first was that she didn’t really think she’d ever stop referring to herself as ‘Mabel.’ Maybe she was now Sasuke, but she’d spent much more time in her old life, and she would always be Mabel Pines. She also didn’t think she’d ever stop thinking of herself as a ‘her’ — being in a boy’s body was _weird,_ but she could deal with it. _Thinking_ of herself as a boy was a whole other matter though. 

 

Secondly — it _really_ didn’t matter if she was technically in a boy’s body, because she was _seriously_ pretty. Well, for a four year old anyway. But she’d probably grow up to be pretty, if Itachi was anything to go by, so Mabel decided that her new family, the Uchihas, were were just really, _really_ lucky when it came to genes.

 

Thirdly — speaking of the Uchihas, _she had so much new family._ In her old world, she’d had her parents, her grandparents, her brother and her Grunkles. Here? There was a whole _compound_ full of family. She had aunts, and uncles, and grunkles and graunts and cousins _everywhere,_ and she might’ve gone a little bit crazy when she first found out. In her defence, she still felt really homesick, so knowing that she had the potential to form so many new bonds really lifted her mood. 

 

(Her favourite family member was definitely Itachi — he was just kind of awesome, and super nice, and never got mad at her no matter what. _And_ he let her play with his hair. And wore all the sweaters she made him, even though they were admittedly pretty bad since she was still getting used to these tiny hands).

 

Lastly — she came to realise that this world was very different from her old one.

 

Everyone — or at least everyone she’d come across so far, which were mostly just Uchihas for now, and that pretty red-haired lady who she’d met when she was a baby, but hadn’t seen again since then — was apparently a ninja. It was kind of cool at first, until she realised that it was extremely bloody and violent, and involved a lot of murder. And that she didn’t really seem to have a choice in her future career since, well, _everyone_ seemed to be doing it. She was _really_ not sure what to think about that. 

 

Well — she wasn’t going to _kill_ anyone. She’d just have to find some way out of it. _And_ find some way to get Itachi out of it, because she was pretty sure he didn’t like killing people (not that she thought any of her new family _liked_ the killing part of their jobs, but Itachi _really_ didn’t seem to like it), and her little big brother was just way too pure (and adorable — so _so_ adorable) for any of this.

 

(He also _really_ didn’t seem to like her constantly calling him ‘adorable’ and squishing his cheeks, but she wasn’t going to stop because a) he was too nice to actually tell her to stop, and b) she was pretty sure he thought the same thing about her. He seemed to have a weird habit of poking her forehead though, but she was pretty quirky herself, so it wasn’t like she was going to judge him for it).

 

In the mean time, if this world was going to be super dark and murder-y, she’d just have to give it some Mabel magic.

 


	2. Itachi

So, apparently this new world was _really_ dark.

 

Mabel had thought that Bill Cypher and Weidmageddon had been bad enough, but at least Bill had been too busy turning people into stone to bother with things like hacking, burning, and stabbing with weird star shaped knife thingys.

 

It was gross and gory. The only good thing about it was that they got to learn cool ninja stuff, like how to clone yourself, and changing your appearance, and breathing _fire._ Mabel couldn’t help but think of Dipper whenever she learnt about these cool new ninja powers. Her brother would’ve loved it.

 

That still didn’t change how dark and murder-y this new world was. As much as she hated to think how _she’d_ handle herself when the time eventually came for her to take her rightful place as a killer ninja, it bothered her even more to think that her _nine year old brother_ was apparently out doing those things.

 

He was _nine._ Seriously, when Mabel was that old — the first time around, because right now, as Sasuke, she was only three — she’d been busy going on adventures with her brother, and doing arts and crafts, and having sleepovers with her friends. 

 

Considering that Itachi was considered a prodigy — which meant that he was thrust into the role of killer ninja even sooner — Mabel was pretty sure he was traumatised enough by this point to need decades of therapy. Mabel decided that she’d kick start the process by making sure he received enough love, and comfort and hugs in-between training and missions, so that he’d at least get somewhat of a normal childhood. As normal of a childhood as you could have in this world, anyway.

 

Itachi was her little brother, after all, and that meant it was Mabel’s job to protect him (…okay, he was her big brother, but _technically_ she was a lot older than him. So that made him her little brother, whether he liked it or not).

 

“Can I play with your hair?” she asked him, trying to sound as cute and loveable as possible. Being three again came with all the benefits of being an adorable toddler, and she was going to use those adorable-toddler-manipulation skills to her benefit. 

 

She wasn’t actually expecting him to say _yes._ Back in her own world, guys tended to very fervently say no whenever she asked if she could do their hair, or nails, or makeup.

 

Itachi didn’t even hesitate. “Okay.”

 

She stared. “…And your nails. I want to do your nails too.”

 

“Fine.”

 

Oh my _God._

 

“I…I love you,” she breathed. 

 

Itachi looked slightly starry eyed. Mabel decided that he was definitely her favourite person in this new world. 

 

Oh and she was going to make him look _so_ pretty. Sure, she was technically supposed to be cheering _him_ up, but she was pretty sure Itachi was happy whenever _she_ was happy, which really broadened her options.

 

She went and raided their mom’s room. Mikoto didn’t wear makeup much — she didn’t really need it. In Mabel’s opinion, she was definitely a natural beauty — but she did have a small collection of nail polish, and enough makeup to make Mabel pause and consider if she'd be pushing it if she brought them along with her when she went back to Itachi’s room.

 

_‘…Well, it doesn’t hurt to ask.’_

 

She made sure to give Itachi an extra-adorable smile when she went back to his room, and made sure that he looked suitably dazed and starry-eyed before she showed him the container of makeup.

 

He hesitated for a moment and then said yes. Mabel didn’t even bother to hold back her squeal. This kid was _awesome_. Also, if he’d existed back in her old world, and they hadn’t been related, she was pretty sure they would’ve been soulmates.

 

Obviously that would never happen _here_ because he was her brother, and that’d just be gross, but she was sure that one day he’d make one lucky girl or guy very happy.

 

(And then Mabel would break their face and beat them to the ground with her cool new ninja powers, because _no_ _one_ was worthy of her adorable little brother. She’d wait to cheer them on _after_ they’d been suitably threatened).

 

Mikoto came into the room to tell them that lunch was ready, and stopped abruptly, staring in shock at the sight of her two sons, hair freshly braided (in Itachi’s case anyway — Mabel had just rammed a bunch of clips into hers. It was _so_ unfair that she didn’t get smooth, silky hair like he did. Her’s kind of looked like a duck’s butt), nails pink and sparkling, and makeup extremely vibrant.

 

Itachi looked like a deer caught in headlights, but Mabel simply beamed widely and said, “Hey Mom! Want us to do your makeup too?” 

 

Mikoto looked like she was struggling to hold back a laugh. “Uh, no, that’s okay, sweetie. You two have fun.”

 

Itachi swallowed, his cheeks turning red, although Mabel wasn’t sure if that was because of the blush she’d admittedly gone a little overboard with, or because he was just really embarrassed.

 

She reached out and pat him on the head. “There, there. You look _really_ pretty.”

 

That didn’t seem to cheer him up much, although Mabel wasn’t sure why.

 

…

 

Shortly after Itachi became a Jounin — which was apparently really high up on the ninja hierarchy — Mabel asked Mikoto if she could take her out to get a new journal. Mikoto didn’t seem that confused by her request, probably figuring that she wanted to use it to draw or something like that.

 

That wasn’t the case. Mabel wanted to use it to record any new or exciting things she found in this new world. She hadn’t really had much time to explore in these past few years; being this young again meant that she was unfortunately really dependent on adults again. 

 

Luckily, Mikoto seemed okay sending her out with Itachi. The kid _was_ really responsible. That worked brilliantly for her current plan, because it was no fun exploring alone. 

 

She glanced down at the journal, and was hit with a sense of nostalgia. Man, Dipper had been crazy about the journals back during their first summer in Gravity Falls. They’d had so many wild, crazy adventures together.

 

She liked to think that Dipper would be pretty proud of her continuing their adventures with their new little brother. And yeah, maybe Itachi was technically just her brother, but Dipper was her twin, and always would be, and that made Itachi his too. She was pretty sure Dipper would agree if he was here.

 

(Wow, she really missed him).

 

…

 

She took Itachi with her to explore the nearby woods the first opportunity they get. They didn't find anything, which kind of sucked, but Mabel decided that there was plenty of time. Besides, it was a ninja village, so they had to have plenty of cool, hidden stuff, right?

 

…

 

Being a Jounin meant that Itachi kept being sent away on long missions. Mabel couldn't help but worry about him — was he warm enough, was he getting enough to eat and drink? 

 

“Don’t worry about me, Sasuke,” he said, smiling. “I’ll make sure to play with you when I get back.” And then he leaned over and flicked her forehead. Mabel still didn’t know why he did that, but it was kind of adorable, so she wasn’t going to complain.

 

“Stay safe!” she said, leaning over and wrapping her arms around him. “I’ve packed your bag, okay? You’ve got a lunch box with sandwiches and dango, and I’ve packed a blanket in there, a change of clothes, a hat — remember, too much sun exposure is _bad —_ our journal in case you see anything cool while you’re on your ninja mission, and your stuffed Weasel, in case you get homesick, or have a nightmare.”

 

She’d gotten him the toy weasel for his birthday, because he was ten, and what ten year old didn’t have toys? He'd looked slightly mortified, and assured her that he didn’t need it, but also hadn't complain too much when he’d realised how much she wanted him to have it.

 

That was good, because Mabel sure as hell wasn’t backing off from that one. Itachi could be a big, scary ninja if he wanted to be, but he was still a little kid, and she was going to treat him like one. And then meant having at least _one_ stuffed toy.

 

Itachi sighed. “Sasuke. I can’t carry all of that.”

 

Mabel pouted.

 

“…Can I leave the stuffed weasel?” 

 

“Mr. Fuzzy stays.”

 

He sighed. “Fine.”

 

Mabel beamed. She heard a snort of laughter from behind her, and glanced back to see Mikoto grinning at the two of them.

 

Itachi left, and Mabel decided that she was really bored. There wasn’t much you could do as a four year old. None of the other kids at the Uchiha compound were her current age, and Mikoto was too busy to play with her right now.

 

She paused, her face lighting up when a thought struck her. 

 

She hurried to her room, looking for the knitting equipment she’d asked Mikoto to buy her earlier that year. Apparently parents were considerably less worried about their kids having sharp objects around here, considering their future careers.

 

She sat down on her bed and got to work. She wanted to be done by the time Itachi got home.

 

This was considerably harder with such tiny hands, but Mabel wasn’t giving up. 

 

…

 

When Itachi got home, Mabel handed him his new sweater, beaming proudly. 

 

“It’s for when you go on missions! Look, it’s all soft and fluffy, and it’ll keep you warm!” She was struck by sudden inspiration. “You could even use it as a blanket!”

 

Itachi stared blankly at the object in his hands. Mabel knew it wasn’t her best work, but it still looked pretty cute. It even had a weasel stitched onto the front (she’d long since decided that weasel’s were going to be Itachi’s thing. It was even in his name!).

 

“It’s…nice. Uh…what’s this…?” He gestured awkwardly at the design stitched onto the front.

 

“It’s a weasel,” she told him proudly.

 

Shisui — who’d come home with him — squinted at it, frowning. “That’s a _weasel?_ It looks like a pile of — ”

 

Itachi shot him a warning glance, cutting him off.

 

“You’ll wear it, right?” Mabel asked, staring at Itachi with wide eyes. Her brother stared back at her, looking startled.

 

“Oh man,” Shisui said, shaking his head.

 

Mabel turned to him. “Oh, sorry, I didn’t have time to make you one to! I’ll get right on it!”

 

He blanched. “Uh, that’s fine.”

 

She shook her head. Shisui was Itachi’s best friend — one of his only friends really, but she was still working on that — and she wasn’t going to have him feeling left out.

 

 

“I’ll make you a really cute one. Do you like pink?”

 

He stared at her, looking slightly horrified. Okay, not pink then.

 

Itachi stared at the sweater for a while longer, and then sighed and slipped it over his head. He glanced down at himself and shrugged lightly. “It feels nice.”

 

Mabel beamed, deciding that she was definitely making him more. And some for herself — she really needed to get back into the hang of making them. 

 

(About a year later, Itachi had basically replaced his entire wardrobe with sweaters. Mabel still wasn’t sure if it was because he genuinely liked them, or if it was to make her happy, but she thought he looked adorable so she wasn’t going to complain).

**Notes for the Chapter:**

> Hope you liked this! I'm going to try and have each chapter focused on Mabel/Sasuke's relationship with a different character :)


	3. Mikoto

Mikoto adored both of her children equally, but she had to admit that Sasuke’s arrival had been the saving grace of her family. She was pretty sure Itachi would readily agree if she voiced these thoughts aloud, and Fugaku probably would too, albeit without so many words.  
  
The thing was, before her youngest had been born, things had been very different. When she thought back to Fugaku’s ever growing distance, the increasing hours he’d spent in his office in the police department and away from home; to Itachi’s solemn face, the way he’d grow quieter and more serious as the days passed, the muffled sobs she heard from at night sometimes, she didn’t think that it was an over exaggeration to say that her family had been on the brink of falling apart.  
  
But Sasuke’s arrival had changed things. The boy was just so bright and cheerful, and more importantly, he just _didn’t give up._ Mikoto had learnt this the first time Sasuke had burst into Fugaku’s office (without her knowledge of course — she’d been frantic, searching all over the place for him) and had repeatedly sprayed his father with _glitter_ of all things until he’d agreed to come home for lunch with the family.  
  
Fugaku had complained about that for the rest of the day, and Mikoto nodded sympathetically, barely able to hide her smirk.  
  
Itachi on the other hand, simply couldn’t say no to his little brother. He’d been besotted with Sasuke from the moment he’d held the boy in his arms for the first time. It wasn’t as if Itachi had changed completely following Sasuke’s arrival — he was still quiet, and serious, and dedicated, but there was also a certain lightness to him that hadn’t existed since the time he’d seen his first dead body.   
  
Because Sasuke’s cheerfulness and excitement was contagious, and Itachi obviously adored the time he spent with his brother. And maybe that wouldn’t have been enough, maybe Itachi still would’ve let his work and training consume him, but Sasuke wasn’t one to take no for an answer. If Itachi was too busy then he’d make time for him. And Mikoto couldn’t help but think that, at times, Sasuke seemed to view himself more as a parent than as Itachi’s little brother.

So yes, she was thankful for the presence of her youngest son, who had somehow pieced her broken family back together, and given her the first glimpse of hope she'd had in years. Sasuke could be strange at times - overly hyper and excitable, eccentric, quirky - but Mikoto loved every part of that, and wouldn't change him for the world.  
  
…

  
The glitter incident happened a few months ago.  
  
Sasuke had run off somewhere, and she had no idea where. She'd been panicking. She didn’t want to disturb Itachi, knowing that her eldest was exhausted after his latest mission, but she wasn’t sure what to do.  
  
Then the front door opened, and a heavy set of footsteps had her on immediate alert. She hurried over, readying herself for a fight, because no one should’ve been coming into her home at this time, and paused in surprise when she saw Fugaku closing the door behind him.  
  
The surprise was soon replaced with relief when she saw Sasuke standing next to him, his hand clasped tightly in his father’s.  
  
“I think you lost something,” Fugaku said dryly. 

  
“Sasuke!” she cried, hurrying over. She bent down so she was at eye level with her son, her expression stern. “I was looking all over for you!”  
  
“Sorry, Mom,” Sasuke said, looking way too cheerful to actually be sorry. “I wanted to get Dad home for lunch.”  
  
(Her son had always had excellent vocabulary for his age. A prodigy in the making, Fugaku would always proudly say, when he wasn’t busy being horrified by his youngest’s usual antics).  
  
“He stopped by my office,” Fugaku ground out. “Mikoto, please, for the love of God, make sure he _never_ does that again.”  
  
“You weren’t coming home for lunch,” Sasuke retorted. “Lunch time is family time, you can’t just not show up!”  
  
“I was working!”  
  
“But you’d rather be having _family time._ I can tell.”  
  
Fugaku turned away from his son, and focused his attention on Mikoto, his expression a mixture anger, frustration and disbelief. “He utterly humiliated me.”  
  
Mikoto snorted. “Oh come on Fugaku, he’s _four_ , what could he have possibly…” And then she got a good look at her husband. “…Oh.”  
  
“Yes oh,” Fugaku spat, angry, and covered head-to-toe in glitter.   
  
“…Oh my God, what did he _do?”_  
  
“He kept spraying me with — with — _this.”_ Fugaku gestured at himself. Next to him, Sasuke held up a spray bottle containing glitter mixed with water, beaming proudly. “He said he’d keep doing it until I left the office and came home for lunch!”  
  
Mikoto had to fight to keep her lips from twitching into a smile. “And what, you, a skilled shinobi, couldn’t stop a four year old boy?”  
  
“He’s a menace,” Fugaku said, scowling darkly. “And what was I supposed to do, throw a kunai at him?”  
  
“I would’ve dodged it,” Sasuke said. “I’m just that good.”  
  
Mikoto reached out and pulled him close, ruffling his hair. “Yes you are, sweetheart.”  
  
“Mikoto!”  
  
She grinned. “Oh come on Fugaku, it’s pretty hilarious. You look ridiculous.”  
  
“He used _glitter.”_ Her husband shook his head, almost pouting, and he looked so ridiculous that Mikoto burst out laughing.  
  
Sasuke tipped his head back, staring seriously at Mikoto. “I ran out of stickers.”  
  
Fugaku let out a groan, running a hand over his face. “Sasuke, promise me you’ll never do that again.”  
  
Sasuke shrugged. “No promises. You have to come here for lunch every day, and _then_ we’re talking.”  
  
“Every — I have work!”  
  
“Fine, not every day, but let’s negotiate.”  
  
Fugaku turned to her. “Are you _hearing_ this?” He looked so incredulous, and Mikoto's laughter only grew. The whole situation was ridiculous, and at the same time, she couldn't remember the last time Fugaku had come home for lunch; he was always so preoccupied with his work at the police department. Regardless of the circumstances, it was nice seeing him here.  
  
Fugaku shook his head, betrayed.  
  
There was the sound of soft footsteps and then Itachi was standing in the doorway, dressed in a fluffy red and blue sweater, looking bewildered.  
  
“What’s going on?”  
  
“Itachi!” Sasuke squealed, running across the room, and throwing his arms around his brother’s middle. “You look adorable! Let’s do your nails so they match, okay?”  
  
Itachi pat Sasuke’s head fondly, and glanced up, frowning when he caught sight of Fugaku. “Why are you covered in glitter?”  
  
Fugaku grimaced.  
  
Mikoto shook her head, still smiling. “Alright, let’s go have lunch then.” The boys hurried ahead, Sasuke still clinging to Itachi, and Fugaku fell into step beside her.  
  
“That boy is going to be ruthless some day. Although he really needs to work on his methods.”  
  
Oh, Mikoto wasn’t so sure. She thought the glitter was actually pretty effective.


End file.
